Filament winding apparatus

ABSTRACT

An apparatus for winding a filament on a straight shank of an intrauterine device includes a rotatably driven chuck to which one end of the IUD is clamped. The straight shank of the IUD is snapped into a notch formed on one end of a bar slidably impaled on a guide spar. The other end of the bar has a threaded semicylindrical groove which engages a rotating threaded rod to cause axial translation of the bar relative to the shank. A slot, communicating with the notch in which the shank is held, is cut into the bar to guide the filament onto the shank in a uniform helix as the chuck and the rod are rotated.

United States Patent 1 Tatum et al.

[111 3,711,035 1 Jan. 16, 1973 [54] FILAMENT WINDING APPARATUS [73] Assignee: The Population Council, Inc., New

York, N.Y.

[22] Filed: Aug. 12, 1971 [21] App1.No.: 171,096

[52] US. Cl ..242/7.01, 128/130 [51] Int. Cl. ..B2lf 17/00 [58] Field of Search ..140/71, 93; 242/701, 7.19,

[56] References Cited UNITED STATES PATENTS 3,142,450 7/1964 Bohannon, Jr. ..242/7.01

3,533,406 10/1970 Tatum ..128/130 Primary Examiner-Lowell A. Larson Att0rneyGranvi1le M. Brumbaugh et al.

[57] ABSTRACT An apparatus for winding a filament on a straight shank of an intrauterine device includes a rotatably driven chuck to which one end of the IUD is clamped. The straight shank of the IUD is snapped into a notch formed on one end of a bar slidably impaled on a guide spar. The other end of the bar has a threaded semi-cylindrical groove which engages a rotating threaded rod to cause axial translation of the bar relative to the shank. A slot, communicating with the notch in which the shank is held, is cut into the bar to guide the filament onto the shank in a uniform helix as the chuck and the rod are rotated.

11 Claims, 4 Drawing Figures 0 PATENTEDJAH 6 I975 SHEETIOFZ 96 7 I0 I08 6 I02 1 n IOOJ / INVENTO I HOWARD TATUM BY NILS A. JERNBERG & JOHN BRAUN QM DMQQW PATENTED JAN 16 I973 SHEET 2 [IF 2 FIG. 2

s a m WM M TUE R NTB 0 E VTR3NT N.E I JW D 7 M N wm w 0'0 h NJ vY Y B BACKGROUND OF THE INVENTION This invention relates to apparatus for winding filaments in a uniform helix, and more particularly to an apparatus for winding a filament on the short, fragile shank of an intrauterine device (IUD).

It has been discovered that intrauterine insertion of a device containing a certain surface area of a physiologically active metal, such as copper, zinc, gold, silver, platinum, tin, iron, aluminum, manganese, and various alloys and combinations of these metals, yields excellent contraceptive effects. It has also been found that a T-shaped device affords excellent reliability of retention within the endometrium cavity. To realize both of these desirable effects in a single device, a T-shaped polyethylene IUD was designed having a filament of copper or one of the other physiologically active metals wound along its leg. This device was tested and the results fully confirmed the theoretical expectations: the contraceptive properties and reliability of intrauterine retention were found to be excellent. Accordingly, plans were made for introducing this device to the public and for manufacturing it on a high volume basis to meet the expected demand.

A major problem arising in development of high volume production techniques for this device was the development of a technique for winding the wire around the leg of the T-shaped IUD. The known wire winding machines were evaluated and found to be unacceptable to this application because of the special problems involved. These machines were generally for the fabrication of long continuous coils of indeterminate length or for the winding of a great length of wire in many layers around a core.

A machine for mass producing wire-wound IUDs requires functional capabilities not found in prior art wire-winding machines. One feature peculiar to this application is the short length of the mandrel or core on which the wire is to be wound and the short length of wire to be wound on the core. Because of the short length of the core and the short length of wire to be wound on the core, this machine must be peculiarly adapted to rapid automatic unloading and reloading of the IUD into the machine. In addition, because of the very fragile nature of the IUD leg, firm support must be provided against lateral forces exerted by the pull of the wire as it is wound onto the leg. Also, because the leg is generally of a very fine diameter, special problems of guidance of the wire onto the leg are encountered in efforts to wind a precise helix of an exact predetermined pitch onto the leg. Finally, the design must be flexibly adapted to the use of different sizes and materials of IUD and filament. For For example it may be desired to use narrow flat ribbons of certain material'instead of wire in which case the alteration to the machine to accept this material must be easily and quickly made.

Thus the need exists for a filament winding machine capable of winding a short length of filament on a fragile small diameter core, and also capable of providing lateral support to the core against the pull of the filament. In addition, the machine must be easily amenable to automatic loading'and unloading of the core and must be flexibly designed to receive cores of various materials and diameters. Moreover, it must be capable of winding filaments of various cross-sectional diameters and designs on these various cores in helixes of varying pitch.

SUMMARY OF THE INVENTION 'ment winding machine capable of winding a short length of filament about a fragile, small diameter core and which is readily amenable to mass production techniques.

A further object of this invention is to provide a filament winding machine which is easily and rapidly reset to start position after the core has been wound and in which the core is easily and quickly inserted and removed.

These and other objects of the present invention are attained by providing a filament winding machine having a rotatably driven chuck mounting an easily operated clamp for holding one end of the IUD. A bar, slidably mounted opposite the chuck for uniform axial translation therefrom, slidably supports the other end of the IUD against the lateral pull of the filament while guiding the filament in a precisely regulated helix about the leg of the IUD.

DESCRIPTION OF THE DRAWINGS A better appreciation of the invention and its many attendant advantages will develop upon consideration of the following detailed description of a preferred embodiment when read in connection with the following drawings, of which:

FIG. -1 is a perspective view of a preferred embodiment of the invention;

FIG. 2 is an exploded perspective view of the chuck and the clamp holding a T-shaped IUD;

FIG. 3 is an enlarged perspective view of the slide bar shown in FIG. 1; and

FIG. 4 is an elevation, partly in section, of an alternative form of the slide bar shown in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, wherein like reference characters designate identical or corresponding parts, and more particularly toFIG. 1 thereof, a filament winding machine is shown having a base 10 including a top shelf 12 and a parallel bottom shelf 14 rigidly held in horizontal vertically spaced relationship thereto by means of four identical vertical legs 16. Bottom shelf 14 extends horizontally forward of top shelf 12 a distance of some 4 inches to accommodate a wire spool as will appear more fully hereinafter.

A pair of parallel, upright, horizontally spaced support blocks 18 and 20 are rigidly secured to top shelf 12 by machine screws extending through holes formed in top shelf 12 and threadedly fastened into threaded holes in support blocks 18 and 20. A hole 22 is formed in each of support blocks 18 and 20 in axial alignment and a bronze bushing 24 is pressed into each hole. The ends of a traverse shaft 26 are joumaled in the bores of bronze bushings 24 and are restrained from lateral displacement by a cylindrical collar 28 on one end and spur gear 30 connected to a similar collar 32 secured to the other end, both gear and collar being secured by a set screw threaded therein and engaging traverse shaft 26. An anti-friction Teflon washer is interposed between collar 28 and support block 18 and also between gear 30 and support block to permit small clearances and thereby assure precise regulation of the helix which the traverse shaft controls, as explained more fully below, while preventing frictional engagement between support block 18 and collar 28, and support block 20 and spur gear 30, respectively.

Motive power for the device is provided by a motor 34 secured to top shelf 12 by means of a suitable mount. A gearbox 36 connects motor 34 with an output shaft 38 on which is mounted a spur gear 40 identical to spur gear 30. Spur gear 40 meshes with spur gear 30 to provide rotational drive to traverse shaft 26.

A chuck 42 is connected to output shaft 38 by means of a set screw 44. The outer face of chuck 42 is formed to receive a spring clamp 46, secured thereto by a screw 48. Clamp 46 provides an easily operable means by which cross arms of a T-shaped IUD may be clamped to chuck 42. Chuck 42, shown in exploded relationship to clamp 46 in FIG. 2, is a cylindrical block having an axial bore communicating with the rear surface 50. A threaded hole 52 communicates with the bore and receives set screw 44 by which chuck 42 may be secured to motor output shaft 38. The front face of chuck 42 has formed thereon a diametrically extending wall 54 having a groove 56 formed in the top or front face thereof. A wide shallow channel 58 is cut into the front face of chuck 42 and extends radially.across the face of the chuck and-ends flush with wall 54. A bore having a wide top portion and a narrow bottom portion is formed in the middle of channel 58 and extends parallel to the axis of chuck 42. A brass bushing 60 is pressed into the wide portion of the bore and protrudes therefrom above the floor of channel 58 a length equal to the depth of channel 58, so the top surface of brass bushing 60 is flush with the portion of the front face of chuck 42 into which groove 58 is cut. The narrow portion .of the bore, axially underlying the portion thereof into which brass bushing 60 is pressed, is threaded to receive screw 48.

Spring clamp 46 is formed of a roughly Z-shaped piece of spring steel of a width equal to the width of channel 58. The clamp is formed of a clamping plate 62 and a clamped plate 64, joined by an axially extending flex plate 66. The middle portion of the clamped plate 64 is laterally humped in a V-form, the vertical rise of which is equal to or just slightly greater than the vertical rise of brass bushing 60 above the floor of channel 58, and has formed therethrough an oval opening 68 aligned to receive brass bushing 60. The axial length of flex plate 66 is equal to the axial rise of wall 54 above the floor of channel 58, and the length of clamping plate 62 is equal to the short transverse width of wall 54. A notch 70 is formed in the middle of clamping plate 62 to receive the leg 72 of T-shaped IUD 74. To provide a handle. by which clamp 46 may be flexed away from wall 54 to permit insertion of IUD leg 72 into groove 56, a bail 76 is soldered or otherwise fastened to and extends radially out from flex plate 66.

To assemble the clamp 46 to the chuck 42, clamped plate 64 is fitted into channel 58 with the protruding portion of brass bushing 60 extending into opening 68 of clamped plate 64. Flex plate 66 lies along the surface of wall 54 and clamping plate 62 lies across and flush with the forward or top surface of wall 54. Screw 48 is inserted through the bore of bronze bushing 60 and is threadedly engaged with the threads in the underlying narrow portion of the bore. The inner surface of the head of screw 48 engages the front face of brass bushing 60 to provide a limit for screw 48, and also engages the top surface of the V-shaped hump in the clamped plate 64 to firmly hold it in position while allowing the entire length of clamped plate 64 to contribute to the flexing action along with flex plate 66. The walls of channel 58 abut the lateral sides of clamped plate 64 to prevent the clamp from skewing around under the influence ofa torque exerted on the IUD leg during wind- In use, bail 76 is grasped with the finger and pulled to flex clamped plate 64 and flex plate 66 away from wall 54. The arms of T-shaped IUD 72 are laid in groove 56 in the top or facing surface of wall 54 and the clamp 46 is allowed to return to rest position. The leg 72 of T- shaped IUD 74 will extend through notch in clamping plate 62 and the arms will be securely held in groove 56. To remove the IUD, the bail 76 is grasped as before and used to flex clamp 46 away from the surface of wall 54. The IUD may then be easily removed from groove 56. Naturally, when automatic unloading and reloading techniques are used, bail 76 will be engaged by an automatically operated lug, as will be apparent to those skilled in the art.

Referring again to FIG. 1, a guide spar 78 is supported at one end thereof in cantilever fashion by extending the end thereof into a bore 80 formed in support block 18 vertically spaced beneath hole 22 therein. Guide spar 78 may be secured in bore 80 by means of a set screw or it may be pressed or otherwise permanently securedin bore 80. A collar 82 identical to collar 28 is secured to the other end of guide spar 78 and secured thereto by means of a set screw.

Guide spar 78 is for the purpose of guiding and pivotally supporting a slide bar 84 best shown in FIG. 3. Slide bar 84 is formed of a short bar of Delrin and has formed centrally therethrough a bore 86 through which extends guide spar 78 for purpose of guiding and pivotally supporting slide bar 84. Below bore 86, a threaded semi-cylindrical groove 88 having an axis parallel to the axis of bore 86 is formed in the front surface of slide bar 84. The threads in groove 88 correspond to the threads on traverse shaft 26 so that rotation of traverse shaft 26 when groove 88 of'the slide bar 84 is engaged therewith will cause slide bar 84 to translate axially along guide spar 78. Groove 88 is normally maintained in engagement. with traverse shaft by the action of a spring 89 fastened at one end to the top portion of bar 84 and at the other end to the rear portion of top shelf 12. Bar 84 tends to rotate clockwise under the influence of spring 89 thereby releasably engaging groove 88 with traverse shaft 26.

A hole 90 having an axis parallel to the axis of bore 86 and a diameter equal to the diameter of the leg 72 of the IUD to be wound with wire is drilled in the upper rear corner of slide bar 84, and the upper corner is then cut away in a notch 92. The two faces of notch 92 form a 1 angle and are formed parallel to the axis of hole 90 and lie along radii thereof. Hole 90 thus communicates with the rear face of slide bar 84 with a 115 opening thereto. The radial extent of this opening into hole 90 is sufficient to permit the leg 72 of IUD 74 to be snapped into and out of hole 90 but is sufficiently small to hold leg 72 in place during operation of the apparatus. v

The top surface of slide bar 84 is beveled to present a downwardly sloping front face and into this front face a slot 94 is cut extending downwardly perpendicular to the front sloping face to communicate with hole 90. Slot 94- is for the purpose of guiding the filament to be wound on leg 72 in a uniform helix as slide bar 84 is axially translated by reason of the engagement of semicylindrical groove 88 with traverse shaft 26.

The filament may be a narrow, flat ribbon or a wire of any desired cross section. It may be smooth or textured to increase its surface area. The filament, illustrated as wire 95, is fed to leg 72 through slot 94 from a spool 96 rotatably supported on a portion of bottom shelf 14 extending forwardly of top shelf 12. Spool 96 is rotatably supported between a pair of horizontally spaced, parallel, upright standards 98 secured to bottom shelf 14 by screws extending therethrough and threadedly engaged with corresponding threaded holes in standards 98. A friction brake is associated with the spindle on which spool 96 is journaled to enable the wire to be maintained under tension.

A wire tensioning structure 100 is pivotally supported on the front portion of standards 98 and includes a pair of parallel arms 102 between which extend a rod 104. The ends of rod 104 extend into a pair of aligned holes formed through the end of arms 102 and are rigidly secured therein by set screws 106. A Teflon sleeve 108 fits loosely on rod 104 and a hole is drilled along a chord of the sleeve, not intersecting the axial bore through which rod 104 extends. The weight of arms 102 and rod 104 acts as a constant tensioning force to smooth out fluctuations which may occur in the wire tension exerted by the friction brake and to assure the maintenance of proper tension on the wire as it is being drawn from the spool and wound onto leg 72.

A limit switch 110 is provided to automatically halt the winding of the wire on leg 72 at any position desired. Limit switch 110 is mounted on a support block 112 which in turn is supported on guide spar 78. Support block 1 12 has formed through one end thereof a bore through which guide spar 78 is received and is rigidly secured thereto at any desired position by means of a set screw which is threadedly secured in the front end of support block 1 12.

Limit switch 110 is electrically connected to a control box 114 which contains a speed control for motor 34 to which it it electrically connected. When slide bar 84 reaches limit switch 110 it trips the switch trigger and cuts the power to motor 34. The motor stops and halts rotation of chuck 42 and traverse shaft 26 thereby providing automatic control.

in operation, the T-shaped lUD is loaded into chuck 42 by simply flexing clamp 46 by means of bail '76 and inserting the arms of IUD 74 into groove 56 of wall 54. The end of wire 95 is threaded through a hole drilled in the leg 72 of IUD 74 near the junction of the leg and the arms. Slide bar 84 is rotated counterclockwise, as viewed in FIG. 1, to disengage the threads in groove 88 with the threads on traverse shaft 26, and is slid to the left until slot 94 is aligned with the hole through leg 72. Wire 95 is laid into slot 94 and the slack in wire 95 is taken up on spool 96 with the tensioning structure 100 in operative position. The motor 34 is started by means of the switch on control 114 and the wire is automatically wound in a uniform helix about leg 72 at a pitch determined by the pitch of the threads on traverse shaft 26. At the predetermined position, slide bar 84 will engage the trigger of limit switch 1 10 thereby halting the operation of motor 34. Leg 72 is snapped out of hole 90 and wire 95 is cut and secured to the end of leg 72. Slide bar 84 is rotated counterclockwise around guide spar 78 against the pull of spring 89, and bail 76 of clamp 46 is grasped and pulled to flex clamp 46 away from wall 54 to allow IUD 74 to be disengaged from slot 56.

Referring now to FIG. 4, an alternative form 84' of the slide bar is illustrated having a flanged bracket 116 mounted on its front face by means of screws 118 or the like extending through holes in the flange 119 of bracket 116 and into threaded holes in the slide bar. Two identical plastic feed wheels 120 and 122 are journaled in peripheral juxtaposition, preferably in peripheral contact on vertically spaced horizontal pivot pins mounted on one face of bracket 116. Each wheel has an annular groove formed in the outside periphery thereof which, at the point of peripheral contact of the wheels, together define a circular opening. A solid ring 124 of a resilient material, such as rubber, having a cross-sectional diameter slightly larger than the circular opening defined by the wheel grooves at the point of peripheral contact, is mounted within the annular groove on the periphery of wheel 120. Since the crosssectional area of the rubber ring 124 is larger than the area of the circular opening within which it is confined at the point of peripheral contact between wheels 120 and 122, the rubber is in compression at that point and exerts a firm pressure against the groove in wheel 122 for a purpose which will appear presently.

A plastic guide block is secured to bracket 116 by screws or the like for the purpose of guiding the wire 95 in between wheels 120 and 122. Guide block 128 is L- shaped, having a base portion 130 and a leg portion (not shown) which lies along the far side of bracket 116 and is secured thereto by a pair of screws or the like. Base portion 130 extends around the front of bracket 116 directly adjacent and in front of the junction of wheels 120 and 122. A hole 134 is formed in base portion 130 directly in line with the junction of the bottom of the groove in wheel 122 and the outside periphery of rubber ring 124 for the purpose of receiving and guiding wire 95 to the feed wheels 120 and 122.

A funnel 136 is attached to bracket 116 on the side of wheels 120 and 122 opposite base portion 130 of guide block 128. Funnel 136 has a wide mouth adjacent the junction of wheels 120 and 122 and decreases in internal diameter toward a small diameter section 137 at the other end which fits within an orifice 138 extending through slide bar 84' and communicating with hole 90' in which the leg of the lUD to be wound with wire is retained.

In use, the free end of the wire 95 is fed through hole 134 in base portion 130 and feed wheel 120 is rotated, either by hand or automatically by an appropriate mechanical means. The end of wire 95 is securely gripped between rubber ring 124 and the groove in wheel 122 by virtue of the compression of the rubber ring at the point of peripheral contact between wheels 120 and 122. Further rotation of wheel 120 feeds the end of wire 95 into funnel 136 which guides it into and through the small diameter section 137 in orifice 138, thence to hole 90' in slide bar 84'. The leg of the IUD, previously inserted into hole 90 with the hole in the leg aligned with orifice 138, receives the end of wire 95 and the winding operation commences as before.

A leaf spring 140 may be screwed to top shelf 12 to bear against an appropriately leveled section 142 on the rear face of slide bar 84'. Leaf spring 140, which extends laterally the full range of travel permitted slide bar 84, urges counterclockwise rotation of slide bar 84, as seen inFIG. 4, to assist or replace spring 89 in engaging the threads in groove 88 with the threads in shaft 26.

The great simplicity and rapidity with which IUD 74 may be removed from the filament winding apparatus facilitates the design of automatic loading and unloading of the IUD into and out of the apparatus. It is clear that a substitution of traverse shafts having different pitches and corresponding substitution of slide bars 84 having corresponding pitches will permit the winding of helixes of any desired pitch on the leg 72. Moreover, the slot 94 in slide bar 84 could be made wider or narrower to accommodate varying diameters of wire or even to permit the winding of a narrow ribbon of physiologically active material on leg 72. Thus the invention is adapted to take virtually any material in any filament form and to wind it in a uniform helix of any desired pitch on the leg 72 of an IUD.

If it is desired to wind a helix of non-uniform pitch on the leg 72 this may be accomplished by substituting a blade having a semi-circular edge for the threaded semfcylindrical groove 88 in slide bar 84. The blade could be pivotally mounted to accommodate extremely sharp pitches in the thread in traverse shaft 26. The edge of the blade would ride in the threads cut in traverse shaft 26 and the helix wound on leg 72 would correspond to the helix of the threads on traverse shaft 26.

Obviously numerous modifications and variations of the above described preferred embodiment are possible in view of this disclosure and the prior art. It is therefore to be expressly understood that the invention may be practiced otherwise while still remaining within the spirit and scope. of the appended claims.

We claim:

1. Apparatus for winding a filament around a straight shank of an IUD, comprising:

means for rotating said IUD about the axis of said shank; bar means for guiding said filament onto said shank and for supporting said shank against lateral forces acting thereon; and

means for effecting axial translation between said bar means and said IUD.

2. The'apparatus defined in claim 1, wherein:

said translation effecting means comprises a rod rotatably supported parallel to said shank axis and having helical threads formed therealong, and means for rotating said rod about its axis;

said bar means comprises a bar slidably supported adjacent said rod and having means formed in one end thereof engageable with said helical threads on said rod, and having formed in the other end of said bar a hole for receiving and supporting said shank, and also having formed in said other end of said bar a slot communicating with said hole for guiding said filament onto said shank;

whereby said thread engageable means engages said threads of said rod while said rod rotating means rotates said rod about its axis to effect translation of said bar means along said rod.

3. The apparatus defined in claim 1, wherein said rotating means comprises:

a motor;

a chuck connected to and rotatably driven by said motor;

a clamp connected to said chuck for clamping said IUD to said chuck;

said clamp comprises a Z-shaped member having a clamped plate by which said clamp is connected to said chuck, a clamping plate for clamping said IUD to said chuck, and a flex plate extending between said clamped and said clamping plate by which said clamping plate may be flexed away from said chuck to permit insertion and removal of said IUD into and out of said chuck.

4. The apparatus defined in claim 3, wherein said rotating means further comprises:

means formed in said clamped plate comprising a V- shaped hump extending laterally across said clamped plate;

means defining a hole through the middle portion of said clamped plate and intersecting said hump;

means defining a channel, having the same lateral width as said clamped plate, formed in said chuck for receiving said clamped plate;

a bushing embedded in said chuck and extending from the middle portion of said channel and into said hole in said clamped plate;

a threaded bore underlying said bushing; and

a screw extending through said bushing and threadedly engaged with said threaded bore for securing said clamp to said chuck.

5. The apparatus defined in claim 4, wherein:

said translation effecting means comprises a rod rotatably supported parallel to said shank axis and having helical threads formed therealong; and wherein said bar means comprises a bar slidably supported adjacent said rod and having a semi-cylindrical. threaded groove formed in one end thereof engageable with said helical threads on said rod, and having formed in the other end of said bar a hole for receiving and supporting said shank, and having formed in said other end of said bar a slot communicating with said hole for guiding said filament onto said shank.

6. Apparatus for winding a filament of physiologically active material on an IUD, comprising:

a chuck;

means for rotatably driving said chuck;

a clamp for clamping one end of an IUD to said chuck;

a bar having means formed therein for receiving the other end of said IUD;

means formed in said bar and communicating with said IUD receiving means for guiding said filament onto said IUD;

means for causing relative axial translation between said IUD and said bar;

whereby, said filament will be wound around said lUD in a helix as said chuck rotates and said axial translation between said bar and said lUD occurs.

7. The apparatus defined in claim 6, wherein said translation causing means comprises:

means formed centrally through said bar defining a bore;

a spar rigidly supported parallel to said chuck and extending through said bore for slidably and rotatably supporting said bar;

a threaded rod rotatably supported parallel to said spar;

means formed in said bar defining a threaded groove and engageable with said rod when said bar is rotated around said spar into engagement with said rod.

8. The apparatus defined in claim 1, further comprismeans for feeding said filament through said bar means to said IUD.

9. The apparatus defined in claim 8, wherein:

said translation effecting means comprises a rod rotatably supported parallel to said shank axis and having helical threads formed therealong, and means for rotating said rod about its axis;

said bar means comprises a bar slidably supported adjacent said rod and having means formed in one end thereof engageable with said helical threads on said rod, and having formed in the other end of said bar a hole for receiving and supporting said shank, and also having formed in said other end of said bar an orifice communicating with said hole for guiding said filament onto said shank; and

said feeding means comprises a pair of peripherally grooved wheels and a resilient ring disposed in one of said grooves, said wheels mounted in peripheral juxtaposition adjacent said orifice whereby said filament will be gripped between said wheels and fed into said orifice when said wheels are rotated.

10. The apparatus defined in claim 6, further comprising:

means for feeding said filament through said bar means to said IUD.

11. The apparatus defined in claim 10, wherein:

said feeding means includes a pair of peripherally grooved wheels, with a resilient ring disposed in one of said grooves, said wheels mounted in peripheral juxtaposition adjacent said guiding means whereby said filament will be gripped between said wheels and fed into said guiding means when said wheels are rotated. 

1. Apparatus for winding a filament around a straight shank of an IUD, comprising: means for rotating said IUD about the axis of said shank; bar means for guiding said filament onto said shank and for supporting said shank against lateral forces acting thereon; and means for effecting axial translation between said bar means and said IUD.
 2. The apparatus defined in claim 1, wherein: said translation effecting means comprises a rod rotatably supported parallel to said shank axis and having helical threads formed therealong, and means for rotating said rod about its axis; said bar means comprises a bar slidably supported adjacent said rod and having means formed in one end thereof engageable with said helical threads on said rod, and having formed in the other end of said bar a hole for receiving and supporting said shank, and also having formed in said other end of said bar a slot communicating with said hole for guiding said filament onto said shank; whereby said thread engageable means engages said threads of said rod while said rod rotating means rotates said rod about its axis to effect translation of said bar means along said rod.
 3. The apparatus defined in claim 1, wherein said rotating means comprises: a motor; a chuck connected to and rotatably driven by said motor; a clamp connected to said chuck for clamping said IUD to said chuck; said clamp comprises a Z-shaped member having a clamped plate by which said clamp is connected to said chuck, a clamping plate for clamping said IUD to said chuck, and a flex plate extending between said clamped and said clamping plate by which said clamping plate may be flexed away from said chuck to permit insertion and removal of said IUD into and out of said chuck.
 4. The apparatus defined in claim 3, wherein said rotating means further comprises: means formed in said clamped plate comprising a V-shaped hump extending laterally across said clamped plate; means defining a hole through the middle portion of said clamped plate and intersecting said hump; means defining a channel, having the same lateral width as said clamped plate, formed in said chuck for receiving said clamped plate; a bushing embedded in said chuck and extending from the middle portion of said channel and into said hole in said clamped plate; a threaded bore underlying said bushing; and a screw extending through said bushing and threadedly engaged with said threaded bore for securing said clamp to said chuck.
 5. The apparatus defined in claim 4, wherein: said translation effecting means comprises a rod rotatably supported parallel to said shank axis and having helical threads formed therealong; and wherein said bar means comprises a bar slidably supported adjacent said rod and having a semi-cylindrical, threaded groove formed in one end thereof engageable with said helical threads on said rod, and having formed in the other end of said bar a hole for receiving and supporting said shank, and having formed in said other end of said bar a slot communicating with said hole for guiding said filament onto said shank.
 6. Apparatus for winding a filament of physiologically active material on an IUD, comprising: a chuck; means for rotatably driving said chuck; a clamp for clamping one end of an IUD to said chuck; a bar having means formed therein for receiving the other end of said IUD; means formed in said bar and communicating with said IUD receiving means for guiding said filament onto said IUD; means for causing relative axial translation between said IUD and said bar; whereby, said filament will be wound around said IUD in a helix as said chuck rotates and said axial translation between said bar and said IUD occurs.
 7. The apparatus defined in claim 6, wherein said translation causing means comprises: means Formed centrally through said bar defining a bore; a spar rigidly supported parallel to said chuck and extending through said bore for slidably and rotatably supporting said bar; a threaded rod rotatably supported parallel to said spar; means formed in said bar defining a threaded groove and engageable with said rod when said bar is rotated around said spar into engagement with said rod.
 8. The apparatus defined in claim 1, further comprising: means for feeding said filament through said bar means to said IUD.
 9. The apparatus defined in claim 8, wherein: said translation effecting means comprises a rod rotatably supported parallel to said shank axis and having helical threads formed therealong, and means for rotating said rod about its axis; said bar means comprises a bar slidably supported adjacent said rod and having means formed in one end thereof engageable with said helical threads on said rod, and having formed in the other end of said bar a hole for receiving and supporting said shank, and also having formed in said other end of said bar an orifice communicating with said hole for guiding said filament onto said shank; and said feeding means comprises a pair of peripherally grooved wheels and a resilient ring disposed in one of said grooves, said wheels mounted in peripheral juxtaposition adjacent said orifice whereby said filament will be gripped between said wheels and fed into said orifice when said wheels are rotated.
 10. The apparatus defined in claim 6, further comprising: means for feeding said filament through said bar means to said IUD.
 11. The apparatus defined in claim 10, wherein: said feeding means includes a pair of peripherally grooved wheels, with a resilient ring disposed in one of said grooves, said wheels mounted in peripheral juxtaposition adjacent said guiding means whereby said filament will be gripped between said wheels and fed into said guiding means when said wheels are rotated. 